Super-sensitized photographic silver halide light-sensitive materials



United States Patent Ofi ice Patented M12211;

3,431,110 This invention relates to photographic light-sensitiveSUPER-SENSITIZED PHOTOGRAPHIC SILVER materials and more particularl y tothe manufacture of HALIDE LIGHT'SENSITIVE MATERHALS dye-sensitisedphotographic silver halide emulsions.

Geoffrey Ernest Ficken, Douglas James Fry, and Elvin Frederick WilliamThurston, Ilford, Essex, England, as- Photograliliic. silver. halideelrfuisms P a certain signors to ford Limited, ford, England, a Britishnatural sensltrvrty to light, but th1s 1s restrrcted to a short range ofwavelengths in the ultra-violet and/or blue recom an N0 {Bi-swing. FiledApr. 8, 1965, Ser. No. 446,733 gions of the spectrum. The effect ofincorporating a sen Claims priority, application Great Britain, Apr. 20,1964, sitising dye is to impart to the emulsion sensitivity to light16,271/54 of other wavelengths. It has been known for some years US. Cl.96-104 6 Clams that by incorporating in the emulsion together with the1/28 sensitising dye a second substance which may or may not v itself bea sensitiser, there may sometimes be imparted to the emulsion anadditional sensitivity beyond that which ABSTRACT OF THE DISCLOSURE canbe regarded as the sum efifect of the separate sub A super-sensitizedcombination of dyes and photO- stances. Combinations of sensitising dyeand another subgraphic silver halide emulsions is disclosed, wherein thestance which give this better result are known as superemulsions containdye of the formula: sensitising combinations.

I Y Z I Ra II2 Rio C=OHC=CH-(CH=OH)n-1C X- B6 R N N 1 R4 at t RE where Yand Z are each selected from the class consisting The present inventionis based on the discovery of a of -S, fise, NR and CI-I:CH-, R and R arenew supersensitising combination of the type just referred each selectedfrom the class consisting of alkyl, carboxy to.

alkyl, carbarnoylalkyl and sulphoalkyl, R is selected from According tothe present invention there is provided a the class consisting of hydrogn and l w r lkyl, 6, photographic silver halide emulsion which containsa sen- R and R taken separately are each selected from the sitising dyeof the general Formula I:

class consisting of hydrogen, halogen, alkyl, aryl, alkoxy andtrifluorornethyl, R and R taken separately are hydrowhere Y and Z arethe same or different and represent gen, R and R taken together formpart of a benzene ring, S, Se, NR or CH=CH-. R and R are the R and Rtaken together form part of a benzene ring, R same or difierent andrepresent alkyl, carboxyalkyl, carand R taken separately are hydrogen, Rand R taken bamoylalkyl or sulphoalkyl, R is H or lower alkyl, Rtogether form part of a benzene ring, R and R taken R R and R are thesame or different and represent a together form part of a benzene ring,R is selected from hydrogen or halogen atom o alkyl, aryl, alk x otrithe class consisting of alkyl and aryl, n is an integer fromfiuoromethyl groups, R; and R are the same or different 1 to 2 and X isan anion, and a dye of formula: and represent a hydrogen atom or,together with R and R form part of a 'benzene ring, R and R are the samef" or different and represent a hydrogen atom or, together U with R andR form part of a benzene ring, R is alkyl R5 Rio or aryl and n is 0 or 1and X is an anion, together with a dye of the general Formula II: R5 CR9 I N N I R7 R11 R4 I 13 RIF Ha I U V I O=CHC|1=OHC S a- R5 C ,L/ Re 1?RIG-"0% \C=O f I where R R R R R R R and R have the values R4 Rm a justassigned, and R and R are lower alkyl, A is selected from the classconsisting of O and NR R and R (CHm are each selected from the classconsisting of hydrogen, SOr 1) alkyl, aralkyl and aryl, and U and V are0. 7

where R R R R R R R and R have the values assigned to them above, R andR are lower alkyl, A is 3 -O, or NR R and R are the same or differentand are hydrogen, alkyl, aralkyl or aryl, and when n in Formula I iseither U or V must be an oxygen atom, the other is O or S, and when n inFormula I is 1, U and V are the same and are 0 or S.

It is preferred that n in Formula I is O and both U and V in Formula IIare 0 and R and R are methyl. In the preferred embodiment of theinvention n in Formula I is O, and Y and Z in Formula I are the same andare either S or Se, and in Formula II U and V are both 0, R and R aremethoxy and R R R R R and R are hydrogen and R and R are methyl. By useof a combination of dyes as just set forth, a valuable effect isobtained as illustrated by the specific examples which are set forthlater herein.

Referring to the general formulae it is to be noted that where alkylgroups are referred to, these are preferably lower alkyl groups i.e.containing 1 to 4 carbon atoms, e.g. methyl, ethyl and propyl, thoughthey ma be higher alkyl groups. Where aralkyl groups are referred tothese may be benzyl, naphthylmethyl or the like and Where aryl groupsare referred to these may be phenyl or naphthyl and may includesubstituent groups such as alkyl or alkoxy groups or halogen atoms whichdo not destroy the sensitising action of the compounds.

Examples of alkoxy groups are ethoxy and methoxy. Examples ofcarboxyalkyl groups are carboxymethyl, carboxyethyl. Examples ofcarbamoylalkyl are carbamoylethyl and carbamoy-lmethyl. An example ofsulphoalkyl is sulphopropyl.

The symbol X represents any anion but will generally be a halide ion ora sulphate, sulphonate, aryl sulphonate or perchlorate ion.

A supersensitising combination as hereinbefore described findsparticular use in increasing the sensitivity of red-sensitizedemulsions. Dyes of Formula I are in general red sensitizers. Dyes ofFormula II are green sensitizers but in combination in an emulsion anenhancement of the red sensitivity is obtained over the red sensitivitydue to the dyes of Formula I without any substantial increase in thegreen sensitivity of the emulsion.

From 0.01 g. to 0.3 g. of each sensitizing dye per 1.5 g. moles ofsilver present in the emulsion can conveniently be used.

Most of the dyes of Formula I are known except where R R R and Rrepresent trifiuoromethyl groups. Dyes containing trifiuoromethylsu-bstituents can be prepared by the methods described in Belgian PatentNo. 648,981.

Dyes of Formula II are prepared by the methods described in BelgianPatent No. 648,046.

The following are illustrative examples of the preparation ofsupersensitised photographic emulsions according to the invention:

EXAMPLES The following dyes were employed Dyes of Formula I (A)Bis-(3-ethy1-2-benzothiazole) trimethincyanine iodide.

(B) Bis-(3-ethyl-S-methyl-Z-benzothiazole) trimethincyanine iodide.

(C) Bis-(5-chloro-3-ethyl-2-benzothiazole) trimethincyanine chloride.

(D) Bis-(3,5-dimethyl-2-benzothiazole) 8 methyltrimethincyanine bromide.

(E) Bis-(3,5-dimethyl-2 benzothiazole) 8 ethyltrirnethincyanine bromide.

(F) Anhydro-bis-(3-2-su-lphoethyl 2 benzothiazole) trimethincyaninehydroxide.

(G) Bis-(3-ethyl 2 benzoselenazole) trimethincyanine bromide.

(H) Bis-(3-ethyl 5-methyl-2 benzosclenazole) trimethincyanine bromide.

(I) Bis (3-ethyl-5-methoxy-2-benzoselenazole) trimethincyanine bromide.

(J) Bis-(1-ethyl-2-quinoline) trimethincyanine iodide.

(K) Anhydro-(1-phenyl-3-4'-sulphobutyl 5trifiuoromethyl-Z-benzimidazole) (3-ethyl-2-benzothiazole)trimethincyanine hydroxide.

(L) (3-ethyl-1-phenyl-5-trifluoromethyl- 2 benzimidazole)(3-ethy1-2-benzothiazo1e) trimethincyanine iodide.

(M) (3-ethyl-1-phenyl-5-trifluoromethyl 2 benzimidazole) (3-ethy1 2benzoselenazole) trimethincyanine iodide.

(N) (3-ethyl-1-phenyl-5-trifluoromethyl 2 benzimidazole)(3-ethy1naphtho[1,2d]thiazole 2) trimethincyanine iodide.

(O )dl ilis-(3 ethyl 2-benzothiazole) pentamethincyanine (P) (3-ethyl-5trifiuoromethyl 2 benzothiazole)(1- ethyI-Z-quinoline) trimethincyanineiodide.

(Q) Bis-(5-chloro-3-ethyl-2-benzothiazole) 9 methyltrimethincyaninechloride.

(R) Bis-(5-chloro-3-ethyl-2-benzothiazole) ,B-ethyltrimethincyaninechloride.

(S) Bis-(3-ethyl-2-benzothiazole) 8 methyltrimethincyanine bromide.

(T) Bis-(3-ethyl-2-benzothiazole) ,6 ethyltrimethincyanine iodide.

(U) Bis-(3-ethyl-5,6-dimethoxy 2-benzothiazole) trimethincyanine iodide.

(V) Bis-(3-ethyl-5-phenyl-2-benzothiazole) fl-ethyltrimethincyanineiodide.

(W) Bis-(3-ethylnaphtho[2,ld]thiazole-2) p-methyltrimethincyaninetoluene-p-sulphonate.

(X) Anhydro-bis-(3-2-carboxyethyl-5-chloro-2 benzothiazole)fl-ethyltrimethincyanine hydroxide.

(Y) (3-carbamoylmethyl-5,6 dimethoxy-2 benzothiazole)(3-ethyl-2-benzothiazole) trimethincyanine iodide.

(Z) Anhydro-(5-ch-loro-3-3-sulphopropy1 2benzothiazole)(3-ethyl-5-methyl-2-benzoselenazole) flethyltrimethincyanine hydroxide.

(AA) (3 2'-carboxyethyl S-methyl-2-benzoselenazole) (5-chloro-3ethyl-2-benzothiazole) B-ethyltrimethincyanine bromide.

Dyes of Formula II (A) Anhydro-bis-( 6 methoxy-3-methyl-2-benzoxazole)fl-(3-methyl 5-oxo 2-3-sulphopropyl-4-isoxazolinyl)- trimethincyaninehydroxide.

(B') Anhydro bis-(3 methyl-6-phenyl-2-benzoxazole) B-( 3 methyl-5oxo-2-3'-sulphopropyl-4-isoxazoliny-l)- trimethincyanine hydroxide.

(C) Anhydro-bis-(3 methylnaphtho[1,2d]oxazole 2) 8-(3-methyl 5-oxo2-3-sulphopropyl-4-isoxazolinyl)- trimethincyanine hydroxide.

(D) Anhydro bis-(3,6 dimethyl-Z-benzoxazole) fi-(S- oxo 1-pheny1-3propyl-2-3-sulphopropyl-4-pyrazolinyl)-trimethincyanine hydroxide.

(E') Anhydro bis-(6 methoxy-3-methyl-2-benzoxa- ZOle) fl-(S-oxo 1phenyl-3-propyl-2-3-sulphopropyl- 4-pyrazolinyl)-trimethincyaninehydroxide.

(F) Anhydro bis-(3,5-dimethy1- 2-benzoxazole) 13-(3-methyl-5-oxo-1-phenyl-2 3'-sulphopropyl-4 pyrazolinyl)-trimethincyaninehydroxide.

(G) Anhydro-bis(5-chloro-3-methyl 2 benzoxazole) B-(3-methyl S-oxol-phenyl 2-3'-sulphopropyl-4- pyrazolinyl)-trimethincyanine hydroxide.

(H) Anhydro bis-(3 methylnaphtho[1,2d]oxazole-2) p-(3 methyl-5oxo-1-phenyl-2-3' sulphopropyl-4- pyrazolinyl) -trimethincyaninehydroxide.

(I) Anhydro (3,6-dimethyl Z-benzoxazole) (3-methy1- 2-benzothiazole),8-(3-methyl-5-oxo-1-phenyl-2-3' sulphopropyl 4-pyrazolinyl)trimethincyanine hydroxide.

(J') Anhydro (3 methyl-Z-benzothiazole) (6-2-methoxyethoxy 3-methyl2-benzothiazole) B-(3-methyl-5-oxo-1-phenyl-2-3'-sulphopr0pyl-4-pyrazolinyl) trimethincyaninehydroxide.

(K') Anhydro bis(3,5,6 trimethyl-Z-benzoxazole) B- 5 (3-methy1 5-oxo2-3-sulphopropyl-4-isoxazolinyl)- trimethincyanine hydroxide.

(L') Anhydro (3,6-dimethyl 2-benzoxazole) (6-methoxy-3-methyl2-benzoxazole) p (3-methyl-5-oxo-lphenyl-2-3'-sulphopropyl4-pyrazolinyl)-trimethincyanine hydroxide.

(M') Anhydro (6-methoxy-3-methyl-2-benzoxazole)(3,

5,6 trimethy-l-Z-benzoxazole) fl-(B-methyl-S oxo-lphenyl-2-3sulphopropyl-4-pyrazolinyl)-trimethincyanine hydroxide.

(N) Anhydro-bis [3-methylnaphtho(2,ld)oxazole-2] fi-(3-methyl-5-oxo-1-phenyl-2-3-sulphopropyl-4pyrazoliny-l)-trimethincyanine hydroxide.

() Anhydro bis-(6-methoxy-3-methyl-2-benzoxazole) fi-(3 methyl--oxo1-phenyl-2-3'-su1phopropyl-4-pyrazolinyl)-trimethincyanine hydroxide.

(P) Anhydro bis (3,6-dimethyl-2-benzoxazole) 8-(1- m-chlorophenyl-3methyl 5-0xo-2-3-sulphopropyl-4- pyrazolinyl)-trimethincyaninehydroxide.

(Q) Anhydro bis (3,5,6-trimethyl-2-benzoxazole) fi-(1-m-chlorophenyl-3-methyl 5 oxo 2-3sulphopropyl-4-pyrazolinyl)-trimethincyanine hydroxide.

(R') Anhydro bis (3-methyl-2-benz0xazole) ,8 (3- methyl 5oxo-2-3'-sulphopropyl-4-isoxazolinyl)-trimethincyanine hydroxide.

(S') Anhydro bis (3,6-dimethyl-2-benzoxazole) fl-(S- oxo-l phenyl2-3'sulphopropyl-4-pyrazolinyl)-trimethincyanine hydroxide.

(T') Anhydro-bis-(3,6-dimethyl-2-benzoxazole) B-(3-methyl-5-oxo-2-3'-sulphopropyl-1-p-tolyl-4-pyrazolinyl)-trimethincyanine hydroxide.

(U') Anhydro-bis- 3-ethyl-2-benzoxazole) fl- 3-methyl-5-oxo-1-phenyl-2-3 '-sulphopropyl-4-pyrazolinyl) trimethincyaninehydroxide.

(V) Anhydr0-bis(3,6-dimethyl-2-benzoxazole) B-( 1-benzyl-3-methyl-5-oxo-2-3-sulphopropy1-4- pyrazolinyl)-trimethincyaninehydroxide.

(W) Anhydro-bis-(3,5,6-trimethyl-2-benzoxazole) fi-(3-p-methoxyphenyl-S-oxo-1-phenyl-2-3'-sulphopropyl-4-pyrazolinyl)-trimethincyanine hydroxide.

The combination of a dye of Formula I and a dye of Formula II was addedto a fast gelatino silver iodobromide emulsion containing 3.2 molpercent of silver iodide. It was found that the dyes could be addedtogether or separately and either before or after the customary additionof general sensitising agents such as sulphur compounds and gold salts.Where appropriate, control tests were made with either one or the otherof the dyes used alone.

The following tables illustrate the effect of the supersensitisation.Speeds were measured with respect to light passing through tricolour redfilter in Table (a) and in Table (b) through a deep red filter (IlfordNo. 206, described in the Ilford Colour Filters handbook, p. 14), speedbeing determined as necessary to give a density of 0.1 above fog andbeing quoted on a log scale in relative terms; higher figuresrepresenting higher speeds.

Table (2); n=0 in Formula I Dye of Formula II per 1.5 g. mol Ag Relativelog speed of Dye of Formula I per 1.5 g. mol Ag emulsion (A) 0.1 g (A)0.1 g (11) 0.1g

Table (2); n=0 in Formula I Dye of Formula I per 1.5 Dye of Formula IIRelative log g. mol Ag per 1.5 g. mol Ag speed of emulsion (A) 0.1 g 3.10 (A) 0.1 g (E) 0.1 g 3. 57 (E) 0.1 g 2.90

(B) 0 1 g 3. 25 (B) 0 1 g (A) 0.1 g 3. 77 (A) 0.1 g 3.20

( 0.1 g 3. 22 (E) 0.1 g (A) 0.1 g 3.65 (A) 0.1 g 3.20

(F) 0.1 g 2.92 (F) 0.1 g (A) 0 1 3. 51 3.16

( g 3.77 (G) 0.1g (I') 0.1g 3.92 (I') 0.1 g 3. 77

(H) 0.1 g 3.48 (H) 0.1 g (A) 0.1 3. 97 (A) 0.1 g 3.16

(K 0.1 3.10 (K) 0.025 g (A) 0.075 g 3.65 (A) 0.1 g 3.25

(K) 0 1 3.16 (K) 0 06g (F) 0.04 g 3. 24 (F) 0.1 g 2.89

(K) 0.1 g 3. 02 (K) 0.025 g (G) 0.075 g 3. 40 (G) 0.1 g 3.15

(K) 0.1 g 3.10 (K) 0.025 g (Hf) 0.075 g 3. 34 (H) 0.1 g 3.30

(L) 0.1 g 2.90 (L) 0.1 g (A) 0 1 g- 3.49 (A) 0 1 g 3. 20

(M) 0 1 g 3. 61 (M) 01g (A) 01g 3.94 (A') 0 1 g 3. 20

(N) 0.1 g 3.56 (N) 0.1g (21) 0.1g 3.82 (A) 0.1 g 3.25

(P) 0.1g 2.68 (P) 0.1g (A) 0.1g 3.60 (A') 0.1 g 3. 15

(Q) 0.1 g 3.65 (Q) 0.1g (A) 0.1 g- 3.78 (A) 0.1 g- 3. 50

(R) 0.1 g 4.00 (R) 0.1 g (A) 0.1 g 4.05 (A) 0.1 g 3. 50

(S) 0.1 g 3.73 (S) 0.1 g 3.88 3. 50

(T) 0.1 g 3.36 (T) 0.1 g 3.65 3. 50

(A) 0 1 g 2.84 (A) 0 1 g 3. 40 (L') 0.1 g 2. 45

2. 84 (A) 0 1 g (N) 0.1 g 2.93

4. A photographic silver halide emulsion which containsbis-(3-ethyl-2-benzothiazole)trimethincyanine iodide andanhydro-bis-(6-methoxy-3 methyl-2 benzoxazole)- 708-(3-mcthyl-5-oxo-1-phenyl-2-3'-sulphopropyl 4-pryrazolinyl)-trimethincyanine hydroxide.

5. A photographic silver halide emulsion which con- N0'rE.Preterredcombination of dyes are H and A, I and A, A and O, C and A and A and A.

We claim as our invention: 1. A photographic silver halide emulsionwhich contains a sensitising dye of the formula:

References Cited UNITED STATES PATENTS 3/1955 Carroll et a1. 96-104 4/19-65 Rosenoff 9610 2 I. TRAVIS BROWN, Primary Examiner.

US. Cl. X.R.

